Brave and the Bold (2007 Series) #1

By Mark Waid & George Perez. 

“Roulette”  The Lords of Luck chapter 1

Featuring Batman and Green Lantern Hal Jordan. 

Green Lantern (Hal Jordan) is flying through outer space when he finds a dead man with a bullet hole in his chest floating before him.  Recognizing that such a mystery requires a great detective, he transmits a signal to Batman at the Batcave.  Oddly enough, there is a similar man lying dead on the floor of the Batcave.